A container for retort packaging, comprising a laminated film having as the outermost layer a layer formed of a cross-linked structure comprising a poly(meth)acrylic acid (A) bonded to a polyalcoholic polymer (B) through an ester bond; and a resin composition characterized by having at least chemical structures (X), (Y) and (Z), a degree of esterification defined by the formula: (degree of esterification) = c/(b + c + d) of 0.01 to 0.5, and a degree of ionization defined by the formula: (degree of ionization) = d/(b + c + d) of 0.01 to 0.9 (wherein b, c, and d represent the molar fractions of the carbon-oxygen double bond of the chemical structures (X), (Y), and (Z), respectively in the resin composition). In chemical structure (X), R0 represents H or CH3; in chemical structure (Y), R0 represents H or CH3; and R represents a structure derived from a polyalcoholic polymer (B); and in chemical structure (Z), R0s, which may be the same or different, represents each H or CH3; Me represents an n-valent metal ion; and n is 1 to 3.